Production of polymers of olefinically unsaturated hydrocarbons with a catalyst of aluminum, aluminum trichloride and a titanium tetrahalide



United States Patent 3,093,625 PRODUCTION OF POLYMERS OF OLEFINICALLYUNSATURATED HYDROCARBONS WITH A CAT- ALYST OF ALUMINUM, ALUMINUMTRlCI-ILO- RIDE AND A TITANIUM TETRAHALIDE Herbert Friederich, Worms,and Wolfgang Lehnerer, Ludwigshafen (Rhine), Germany, assignors toBadische Anilln- & Soda-Fabrik ,Aktiengesellschaft, Ludwigshafen(Rhine), Germany No Drawing. Filed Oct. 2, 1956, Ser. No. 613,396 Claimspriority, application Germany Oct. 28, 1955 1 1 Claim. (Cl. 26088.2).

This invention relates to the production of polymers of olefinicallyunsaturated hydrocarbons in the presence of catalysts.

It is known to polymerize ethylene in the presence of a mixture ofaluminium chloride, titanium tetrachloride and .a metal binding hydrogenchloride, in particular aluminium, under increased pressure,advantageously-at 30 to 80 atmospheres or more, and at elevatedtemperature, preferably at 130 to 180 C. (German patent specificationNo. 874,215).

We have now found that olefinically unsaturated hydrocarbons can bepolymerized to high molecular weight solid and tough products even atlow temperatures, as for example even at room temperature, and underlower pressures, even under normal pressure, with the aid of a reactionproduct of a reducing metal of the 1st to 3rd groups of the periodicsystem of elements and the halide of a metal of the 4th to 6thsubgroups.

Suitable olefinically-unsaturated hydrocarbons are in particularolefines, especially having up to about 8 carbon atoms and in particularhaving up to about 4 carbon atoms, such as ethylene, propylene,butylene, or isobutylene and also mixtures thereof, and also diolefines,as for example butadiene or isoprene, as well as vinyl hydrocarbons, inparticular styrene and its derivatives, as for example its alkylderivatives.

For the preparation of the catalyst, a halide of a metal of the 4th to6th subgroups is allowed to react with a reducing metal of the 1st to3rd groups. Suitable halides of the 4th to 6th subgroups are for exampletitanium tetrachloride, titanium trichloride, titanium tetrabromide,halides of Zirconium or hafnium, vanadium tetrachloride, vanadiumoxytrichloride (vanadium-Voxychloride), halides of niobium or tantalum,chromium trichloride, chromyl chloride (CrO Cl and halides ofmolybdenum, tungsten and uranium. Suitable reducing metals are inparticular aluminium, sodium, magnesium and zinc, but all metals of the1st to 3rd groups can be used.

The reducing metals may be used in the form of powder, granules, wire,sheets or foil-s or as colloidal solutions. Metal alloys may also beadvantageous. The mixture may for example be heated for a few minutes attemperatures up to the boiling point of the metal halide. In this way,when using titanium tetrachloride, a partial reduction to titaniumtrichloride takes place. The duration of the heating and the temperaturethereof may be varied within wide limits. Thus a mixture of titaniumtetrachloride and aluminium can be heated in a closed vessel totemperatures up to about 300 C., or also shaken for a long time at roomtemperature. It is especially advantage-ens to carry out the reactionwhile excluding air and moisture. It is of special advantage for thereducing metal to have a large surface. For this purpose it may eitherbe finely divided or also used in compact form, for example as a thinsheet. The polymer can then readily be separated mechanically from themetal or with the aid of solvents. The metals may advantageously only bepartly reacted with the metal halides, so that metal is present inexcess. Also in the case of a complete conver- Patented June 11, 1963ice sion, metal may be subsequently added to the reaction product. Themetal halides may also be allowed to act on the reducing metals in sucha way that the latter is coated with a thin film of the reactionproduct. Obviously, however, larger amounts of metal halide may also beused.

It is often especially favorable to employ in addition an aluminiumhalide. The aluminimum halide is used in amounts up to about 50% withreference to the halide of a metal of the 4th to 6th subgroups, but itmay also be used in an excess up to about 5 times. It is possible toallow the aluminium halide, just like the halide of a metal of the 4thto 6th subgroups, to act in vapor form on the reducing metal. Thealuminium halide may also first be allowed to react with the metal, andthe halide of the metal of the 4th to 6th subgroups then added.

The reaction can be carried out in the presence of indiiferent solventsor diluents, as for example in particular saturated aliphatic,cycloaliphatic or aromatic hydrocarbons, such as pentane, octane,gasoline or gasoline fractions, cyclohexane, tetrahydronaphthalene,decahydronaphthalene, benzene, toluene, xylene, ethylbenzene ornaphthalene. The use of aromatic hydrocarbons has a quite specialfavorable effect.

The catalysts thus prepared may be used directly for the polymerizationof olefinically unsaturated hydrocarbons. It is also often especiallysuitable first to free the resultant catalyst from excess metal halidewith indifferent organic liquids, such as benzene or cyclohexane, orhalogen-containing hydrocarbons. The metals coated with a thin surfacefilm of the reaction product are already highly active catalysts. Theunpurified or extracted catalyst is preferably suspended in anindifferent organic diluent, in particular in the solvents alreadyspecified above. a

The polymerization of the olefine hydrocarbons and in particular ofethylene may be carried out even at room temperature and under normalpressure. It is preferable to cool during the polymerization.Polymerization may also be effected at moderately raised temperatures,and if desired also at temperatures below room temperature, as forexample at 0 C. or even lower. Polymerization may be continuous ordiscontinuous. Obviously it is possible to work under increasedpressure, for example up to about 200 atmospheres and especiallypreferably between about 20 and 50 atmospheres.

By the polymerization of ethylene a loose powder is obtained which isespecially easy to purify. The properties of the polymer may be varieddepending on the composition and the nature of the pretreatment of thecatalyst. The purification of the polymer may be carried out for exampleby washing with organic solvents, as for example alcohols or ethers,which may contain inorganic or organic acids. When using large pieces ofmetal as components of the catalyst, the metal can be separatedmechanically and the polymer then purified with hydrochloric acid inmethanol, with alcohols or with other organic solvents. The polymersobtained contain very small amounts of impurities. They may be used forall purposes for which olefine polymers are customarily used, as forexample for injection molding masses and for the production of foils,films and threads. Obviously waxlike or highly viscous polymers may alsobe obtained with suitable reaction conditions. a

The following examples will further illustrate this invention but theinvention is not restricted to these ex-. amples. The parts specifiedare parts by weight.

Example 1 4 parts of aluminium powder, 1.7 parts of titanium-4- chlorideand 0.2 part of aluminium chloride areheated 3 at 136 C. for 10 minuteswhile excluding air. The mixture thereby becomes colored red with theformation of titanium-3-chloride. It is suspended in 50 parts ofcyclohexane and charged into an autoclave under nitrogen. Ethylene isthen forced in at room temperature up to a pressure of 50 atmospheres.After 8 to 12 hours, the polymerization is completed.

After purification with methanolic hydrochloric acid andtetr-ahydrofurane, 204 parts of solid, film-forming polyethylene areobtained. The melting point is 128 to 131 C.

Example 2 parts of aluminium powder, 5 parts of titanium-4- chloride,0.5 part of aluminium chloride and 17 parts of benzene are heated at 80C. for 2 hours while excluding air and then diluted with 30 parts ofcyclohexane. A vigorous current of ethylene is led into the mixture atroom temperature and under normal pressure. Solid polyethylene therebyseparates out, and is separated after 5 hours and purified by treatmentwith methanolic hydrochloric acid and tetrahydrofurane.

Example 3 2 parts of aluminium powder, 3.4 parts of titanium-4-chloride, 1 part of aluminium chloride and 14 parts of benzene areheated for 2 hours at 60 C. while excluding air. The mixture is thendiluted with 40 parts of benzene and treated in an autoclave withethylene under a pressure of 50 atmospheres at room temperature. Afterpurification with methanolic hydrochloric acid and tetrahydrofurane, 100parts of solid polyethylene are obtained having the melting point 126 to129 C.

Example 4 2 parts of aluminium powder and parts of titanium- 4-chlorideare heated at 136 C. for 3 hours. The mixture is charged into anautoclave together with 78 parts of cyclohexane. Ethylene is forced inat room temperature up to a pressure of 200 atmospheres. The reaction isended after 8 to 12 hours. After purification with methanolichydrochloric acid and tetrahydrofurane, 176 parts of solid polyethyleneare obtained having the melt ing point 126 to 129 C.

Example 6 2 parts of sodium powder, 6.8 parts of titanium-4- chlorideand 78 parts of cyclohexane are heated for 2 hours at 80 C. whileexcluding air. Ethylene is then forced into this mixture under apressure of 200 atmospheres in an autoclave at room temperature. Afterpurification with methanolic hydrochloric acid and tetrahydrofurane, 140parts of solid polyethylene are obtained.

Example 7 2 parts of aluminium powder and 10 parts of titanium-4-chloride are heated for 3 hours at 136 C. while excluding air. Themixture is then shaken With 60 parts of benzene. This benzene solutionis then decanted from the aluminium powder. The aluminium powder iswashed twice more in this Way While excluding air and then suspended in63 parts of cyclohexane. Ethylene is forced into this suspension under apressure of 20 atmospheres in an autoclave at room temperature,

After 20 hours, 140 parts of solid film-forming poly- 4. ethylene havebeen formed which are purified by treatment with methanolic hydrochloricacid and tetrahydrofurane. Its melting point is 130 to 136 C.

Example 8 2 parts of aluminium powder, 10 parts of titanium-4- chlorideand 1 part of aluminium chloride are heated for 10 minutes at 136 C. Thereaction mixture is then purified as described in Example 7 by treatmentthree times, each time with 60 parts of cyclohexane. The aluminiumpowder pretreated in this way is charged together with 63 parts ofcyclohexane into an autoclave. Ethylene is then forced in at roomtemperature up to a pressure of 20 atmospheres. After 20 hours, pants ofsolid, film-forming polyethylene are obtained which are purified bytreatment with methanolic hydrochloric acid and tetrahydrofurane. Themelting point is 130 to 133 C. Example 9 10 parts of aluminium chips, 10parts of titanium-4- chloride, 1 part of aluminium chloride and 88 partsof benzene are heated for an hour at 80 C. while excluding air. Thealuminium chips are then separated from the reaction mixture and chargedtogether with 150 pants of oyclohexane into an autoclave. Ethylene isforced in at room temperature up to a pressure of 200 atmospheres. After12 hours, parts of solid, film-forming polyethylene are obtained havingthe melting point to 135 C.

Example 10 16 parts of aluminium chips, 25 parts of titanium-4-chloride, 1 part of aluminium chloride and 70 parts of xylene are heatedfor 45 minutes at 120 C., while excluding air. The aluminium chips arethen separated from the reaction mixture and charged together with 70parts of cyclohexane into a vessel while excluding air. A vigorousstream of pure ethylene is led into this mixture at room temperature andunder normal pressure. Solid polyethylene thereby separates and iswithdrawn after 5 hours.

Example 11 2 parts of aluminium powder and 4 parts of aluminium chlorideare heated for 2 hours at C. in a closed vessel. To the cooled mixturethere are added at room temperature 3 parts of titanium tetrachlorideand 6 parts of benzene. After a few minutes, a brown reaction product isformed and this is introduced together with 400 parts of heptane into anautoclave. Ethylene is forced into the autoclave at 20 C. under apressure of 20 atmospheres. After 30 hours, 200 parts of polyethyleneare obtained having the softening point 134 C.

Example 12 1 part of aluminium powder, 2 parts of aluminium chloride,1.5 parts of titanium tetrachloride, 5 parts of benzene and 25 parts ofcyclohexane are treated in an autoclave for 20 hours at 20 C. withethylene under 20 atmospheres pressure. 37 parts of polyethylene areobtained which softens at 142 C Example 13 1.5 parts of aluminiumpowder, 5 parts of titanium tetrachloride, 3 parts of aluminium chlorideand 180 parts of benzene are heated for 1 hour at 80 C. The reactionmixture is diluted in an autoclave with 700 parts of cyclohexane.Ethylene is then forced in under a pressure of 20 atmospheres at 25 C.The reaction temperature is kept constant by cooling the autoclave. 750parts of polyethylene are obtained of the molecular weight 200,000. Themolecular weight is determined viscometrically.

Example 14 3 parts of aluminum granules, 5 parts of titaniumtetrachloride and 1 part of naphthalene are heated for 2 hours at 140 C.After cooling, the reaction mixture is washed with benzene and thensuspended in 30 parts of gasoline. In an autoclave, ethylene is allowedto act on the suspension under a pressure of atmospheres at roomtemperature. 75 parts of polyethylene are obtained.

Example 1 part of aluminium powder, 5 parts of aluminium bromide, 5parts of titanium tetrabromide and 100 par-ts of benzene are heated for1 hour at 80 C. and then charged into an autoclave with 150 parts ofcyclohexane. Ethylene is forced in under a pressure of 40 atmospheres at60 C. 150 parts of polyethylene are obtained.

Example 16 1 part of magnesium powder, 1 part of aluminium chloride, 2parts of titanium tetrachloride and parts of benzene are heated underreflux for 1 hour. The reaction product is introduced with 30 parts ofcyclohexane into an autoclave and treated with 40 atmospheres ofethylene at room temperature. 10 parts of film-forming polyethylene areobtained.

Example 17 Polymerization is carried out as in Example 16 but zincpowder is used instead of magnesium powder. 15 parts of film-formingpolyethylene are obtained.

Example 18 0.5 part of aluminium powder, 2 parts of chromium-III-chloride, 1 part of aluminium chloride and 20 parts of benzene areheated for 1 hour at 80 C. and then charged with 30 parts of cyclohexaneinto an autoclave. 20 atmospheres of ethylene are forced in at roomtemperature. 8 parts of polyethylene are obtained which melts intherange of 134 to 148 C.

Example 20 By using in Example 19 the same amount of chromium-II-chloride instead of the chromium-III-chloride, 9 parts ofpolyethylene are obtained.

Example 21 Polymerization is carried out as in Example 19 but the sameamount of vanadiurmV-oxychloride is used instead 0fchromium-III-chloride. 10 parts of film-forming polyethylene areobtained.

Example 22 1 part of aluminium powder and 2 parts of aluminium chlorideare heated in a closed vessel at 180 C. for 1 hour. The cooled mixtureis then treated at room temperature with 1.5 parts oftitanium-4-chlor-ide and 4 parts of benzene. A brown reaction product isthus formed. The mixture is diluted with 1100 parts of heptane. Amixture of 30 parts of styrene and 30 parts of heptane is allowed todrip into the resultant suspension while stirring at C. The operation iscarried out under nitrogen. The polystyrene obtained is freed fromcatalyst by washing with methanol and methanolic hydrochloric acid.

Example 23 If isoprene be polymerized in accordance with the descriptionin Example 22, a solid, brittle polymer is obtained after washing withmethanolic hydrochloric acid.

Example 24 10 parts of aluminium chips are heated for 1 hour at C. with3 parts of titanium tetrachloride, 2 parts of aluminium chloride and 50parts of benzene. The chips are then separated from the reactionsolution under nitrogen and charged with 60 parts ofdecahydronaphthalene into an autoclave. Ethylene is forced in at C. tothe extent of 20 atmospheres. Polyethylene thereby forms at the chips.The polyethylene is dissolved away from the chips by heating withfurther decahydronaphthalene at C. By cooling the solution, the polymerseparates out. After drying, 17 parts of film-forming polyethylene areobtained.

What we claim is:

A polymerization process which comprises contacting a normally gaseousmonoolefin with a three component catalyst initially consisting ofmetallic aluminum, a titanium tetrahalide and aluminum trichloride,wherein the alutrichloride is present in a minor molar ratio withrespect to the molar total of the other two components and recovering apolymer product which is predominantly solid.

References Cited in the file of this patent UNITED STATES PATENTS2,721,189 Anderson et a1 Oct. 18, 1955 FOREIGN PATENTS 874,215 GermanyApr. 20, 1953 538,782 Belgium Dec. 6, 1955 533,362 Belgium Aug. 31, 1955534,792 Belgium I an. 3.1, 1955

